Azure Functions are one of the most interesting technologies in terms of ease of use, cost efficiency and integration with other Azure services. In a mini presentation we will cover latest developments with the service - Azure Function Proxies. Azure Functions Proxies - they allow you to start building easily API-s based on Azure Functions. With the help of proxies you can modify access URL to your Azure Function and use dynamic parameters. Versioning is also a lot easier with proxies.

1. Azure Functions Proxies
Kanio Dimitrov

2. Process events with Serverless code
architecture
An event-based Serverless compute experiences to
accelerate your development. It can scale on demand and
you pay only for the resource you consume.

3. Main Characteristics
• Serverless
• Accelerate development
• Bind to Services
• Rich Language Support
• Pay only for what you use

4. Scenarios
• Time-based
Processing
• Azure Service
Event
Processing

5. Scenarios
• SaaS Event
Processing
• Serverless
web app

6. Scenarios
• Serverless
Mobile Backend
• Real-time
stream
processing

7. Scenarios
• Real-time bot
messaging

8. Azure Functions vs Web Jobs
 Triggers
 Binging Outputs
 Dynamic Plan
 Serverless -> Azure Functions

9. Comparison

10. Monolith
Client app.js
GET /games
GET /users
Pros:
• Speed of
development
Cons:
• Tighter coupling
• Complexity

11. Microservices
Client users.js
GET /users
POST /users
DELETE /users/:id
Client games.js
GET /games
POST /games
DELETE /games/:id
Pros:
• Separation of
concerns
• Less Complexity
Cons:
• Slower deployments

12. Nanoservices
Client get_users.js
GET /users
Pros:
• Greater separation
of concerns
• Even Less
Complexity
Cons:
• Event Slower
deployments
Client delete_users.js
DELETE /users/:id
Client get_games.js
GET /games
Client delete_game.js
DELETE /games/:id

13. Hybrid
Client users.js
GET /users
DELETE /users/:id
Client get_games.js
GET /games
Client delete_game.js
DELETE /games/:id

14. API Development with Azure Functions
• Difficult to manage large solution in single function app
• Deployment isolation between individual components
• Works for triggers, but difficult for APIs
• Each app has a host name, difficult to track
• Difficult for clients, especially when switching for testing

15. Azure Functions Proxies (Preview)
• Easier to develop APIs by using Azure Functions
• Define API surface for multiple functions apps
• Any endpoint can endpoint as reverse proxy to another
API:
• Same function app
• Another function app
• API App
• Any API

16. Demo – Create First Azure Functions Proxy

17. Modifying Backend Requests - Request
Parameters
• Parmeters from route template as inputs for backend URL property
• User “{}”:
• Proxy - /pets/{petId}
• Backend – https://<app>.azurewebsites.net/api/pets/{petId}
• Wildcard
• Proxy - /api/{*restOfPath}
• restOfPath – string representation of the remaining path segments from
incoming request

18. Modifying backend requests - Using
application settings
• Reference app settings by surrounding the setting name with ‘%’
• In https://%ORDER_PROCESSING_HOST%/api/orders,
ORDER_PROCESSING_HOST is coming from app settings
• Use app settings for backend hosts when multiple deployments or
test environments

19. Demo – Modifying Backend Requests

20. Demo – Versioning

21. Deployment
• Configuration stored in proxies.json

22. Azure Functions Proxies vs API Management
Topic Azure Functions
Proxies
API Management
Focus API Development Packaging and
Selling APIs
Features Routing (for now) Advanced
(throttling,
security, caching)
Price Cheaper (pay per
use)
Monthly Fee

23. Architecture
Mobile App
API
Management
Azure
Functions
Proxy
API APP
Function App
REST Endpoint